This article deals with the storage of Lead Acid batteries. As most are aware, there are multiple versions of the traditional lead-acid battery which include Gel, Flooded, AGM etc, however, from a storage perspective they all have similar requirements. The most common battery used in the RV market is the AGM as it requires less maintenance and less chance of venting noxious and dangerous gases. AGM does absorb the majority of the gases created internally in an AGM battery however if there is an excessive build-up due to incorrect charging. These batteries will all “vent” when there is a build-up of gas pressure inside and whilst to the naked eye it may not be obvious, there will be a small vent(s) built into the top of the plastic case (or sometimes the top of the side wall) that allows for excess gas to pass through and reduce the internal pressure of the battery.  Without this vent, the battery could swell within its case and cause even more damage.  This can be seen sometimes when a 2V cell within the battery has been damaged and it continues to overcharge, and the gases can’t vent adequately to protect the battery integrity.